Photochromic compound

ABSTRACT

The present invention relates to a photochromic compound represented by the formula   WHEREIN R1 and R2 each is an alkyl group having one to five carbon atoms or a phenyl group, R3 is a hydrogen atom, an alkyl group having one to five carbon atoms, a halogen atom, a nitro group, a cyano group, a carboxyl group substituted by an alkyl group having one to five carbon atoms, or an alkoxyl group, R4 and R5 each is a hydrogen atom, a nitro group, a halogen atom, a formyl group or an alkoxyl group, X is a cyano group or a carboxyl group substituted by an alkyl group having one to five carbon atoms, and n is 1 to 4.

United States Patent Ono et al.

[15] 3,692,800 [451 Sept. 19, 1972 [s41 PHOTOCHROMIC COMPOUND [72] inventors: Hisatake Ono; Chiaki Osada, both of Asaka-shi, Japan [73] Assignee: v Fuji Photo Film Co. Ltd., Ashigaro- Kamigun, Kanagawa, Japan 221 Filed: Oct. 30,1969 211 Appl.N0.:872,604

[30] Foreign Application Priority Data Oct. 30, 1968 Japan ..43/79l52 [52] 0.8. CI. ..260/326.ll, 117/34, 252/300 [51] Int. Cl. ..C07d 27/38 [58] Field of Search ..260/326.1l

[56] References Cited UNITED STATES PATENTS 3,242,122 3/1966 Cheng ..260l326.l1 X

[57] ABSTRACT wherein R and R, each is an alkyl group having one to five carbon atoms or a phenyl group, R is a hydrogen atom, an alkyl group having one to five carbon atoms, a halogen atom, a nitro group, a cyano group, a carboxyl group substituted by an alkyl group having one to five carbon atoms, or an alkoxyl group, R and R, each is a hydrogen atom, a nitro group, a halogen atom, a formyl group or an alkoxyl group, X is a cyano group or a carboxyl group substituted by an alkyl group having one to five carbon atoms, and n is l to 4.

6 Claims, 1 Drawing Figure PATENTED 19 I973 3.692.800

DENSITY D) WAVE LENGTH INVENTORS HISATAKE 0N0 CHIAKI OSADA SL jLJuJ M BY 21M 4 W" ATTORNEYS PHOTOCIIROMIC COMPOUND BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to photochromic compounds and compositions.

2. Description of the Prior Art A compound represented by the above formula, in which X is a hydrogen atom, is publicly known as a photochromic compound. However, the compound is remarkably affected by polarity during practical use as a photochromic compound, and therefore, has the defeet that the selection range of a high molecular weight material used as a carrier and a solvent used in combination therewith is very narrow.

It has now been foundthat, as in the present invention, when an anion group is introduced as X at the end of an alkyl group, this defect of the compound disappears, and the color density at the time of coloring is improved.

SUMMARY OF THE INVENTION A novel photochromic compound is provided,

represented by the formula:

wherein R and R each is an alkyl group having one to five carbon atoms or a phenyl group, R is a hydrogen atom, an alkyl group having one to five carbon atoms, a halogen atom, a nitro group, a cyano group, a carboxyl group substituted by an alkyl group having one to five carbon atoms, or an alkoxyl group, R, and R each is a hydrogen atom, a nitro group, a halogen atom, a formyl group or an alkoxyl group, X is a cyano group or a carboxyl group substituted by an alkyl group having one to five carbon atoms, and n is l to 4.

Novel compositions are also provided.

Objects of the invention are to provide improved photochromic compounds and compositions.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a plot of wavelength versus density for a compound of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention relates to a photochromic compound represented by the formula halogen atom, a nitro group, a cyano group, a carboxyl group substituted by an alkyl group having one to five carbon atoms, or an alkoxyl group, R, and R each is a hydrogen atom, a nitro group, a halogen atom, a formyl group or an alkoxyl group, X is a cyano group or a carboxyl group substituted by an alkyl group having one to five carbon atoms, and n is I to 4.

The compounds represented by the above formula are colorless when dissolved in a non-polar solvent such as benzene, toluene, etc., and turn greenish blue when irradiated with ultraviolet rays.

Also, a film prepared by dissolving the present compound in polystyrene, polymethylmethacrylate, polyethylmethacrylate, or polyvinyl acetate, etc. using benzene, toluene, ether, cyclohexane, or n-heptane, etc. as a solvent, and coating and drying the resulting solution on an appropriate support, is colorless before irradiation with ultraviolet rays but turns greenish blue upon irradiation with ultraviolet rays. Upon being allowed to stand in the dark or upon being heated, the compound returns back to its original colorless state. Such a treatment can be repeated multiple (several tens) times. As the above described supports, common paper, baryta paper, high molecular weight resinous support, such as polyethylene terephthalate, cellulose triacetate films, etc., glass metals, etc. can be used.

The composition of the present invention is colorless in its ordinary state, but, upon being irradiated with sun light, ultraviolet rays from a mercury lamp, etc. thereon, turns blue or bluish green. The compound returns to its original stage upon being allowed to stand in the dark or upon being heated.

FIG. 1 is a graph showing the change in the absorption spectrum of a film coated with the photochromic composition of the present invention and dried, the absorption spectrum being shown both before and after irradiation with ultraviolet rays. Specifically. FIG. I shows the change of absorption spectrum of the compound represented by the above formula in which X is a nitrile group, R, and R are a methyl group, R. is 5 CH R is 6'-NO and R is a hydrogen atom.

In FIG. I, numeral I shows the change before irradiation with ultraviolet rays and numeral 2 shows the changes after irradiation. A mercury lamp (made by Toshiba SHE-I00) was used as the light source.

The compound represented by the above formula is generally obtained by dissolving a 2-methyl indolenine derivative and a salicylaldehyde derivative in absolute ethanol, adding triethylamine thereto, refluxing, distilling out the solvent after reaction, and appropriately treating the residue.

Photochromic materials using the present compound are exemplified by photochromic materials used for photography and printing, which are obtained by coating the above-described composition onto a high molecular weight resinous base, or a baryta paper, etc.; photochromic materials for furniture, obtained by coating a curtain, glass, etc.; and a photochromic material used as a filter, etc.

EXAMPLE I 10 g. of I-7-cyanopropyl-2,3,B-trimethylidolenium bromide and 5.5 g. of S-nitrosalicylaldehyde were dissolved in cc. of ethanol and, after adding 4.2 g. of triethylamine, refluxed for about I hour. The reaction liquid became dark reddish violet and a yellow crystal was gradually produced. The crystal, after cooling, was

filtered, washed with ethyl alcohol, and, after drying, was recrystallized from ethyl alcohol to obtain 5.3 g. of the yellow crystals of 1--y-cyanopropyl-3,3-dimethyl-6- nitrospiro(indoline-2,2-2'H-chromene). lts melting point was 156 to 158C. The photochromic material obtained by coating a solution of thiscompound in benzene-polystyrene onto a polyethylene terephthalate film and then drying was colorless in its ordinary state, but, upon being contacted with a photographic positive film or negative film and irradiated with ultraviolet rays, was colored to give a blue positive or negative image at those portions where the light was transmitted. The image thus obtained returned to its colorless state upon being allowed to stand in the dark.

EXAMPLE 2 4.l g. of 1-'y-ethylcarboxypropyl-2,3,3-triethylindolenium bromide and 2.1 g. of S-nitrosalicylaldehyde were reacted in the same manner as in Example 1 to obtain 2 g. of the yellow-white crystals of l-y-ethylcarboxypropyl-3,3-dimethyl6-nitrospiro(indoline-2,2'-2' h-chromene). its melting point was 1 17 to l 18C.

The material obtained by coating a solution of this compound in an ethyl acetate solution of polymethylacrylate onto a baryta paper and drying it was colorless, but it immediately turned blue when irradiated with ultraviolet rays. This returned to the original colorless state upon being allowed to stand in the dark or upon being heated. This could be repeated several tens times.

EXAMPLE 3 3.5 g. of l-'y-cyanopropyl-2,3,3-trimethyl chloroindolenium bromide and 2 g. of 3-methoxy-5- nitro-salicylaldehyde were reacted in the same manner as in Example 1 to obtain l.8 g. of the faint green crystals of l-'y-cyanopropyl-3,3-dimethyl-6'-nitro-8'- methoxyspiro (indoline-2,2'-2'H-chromene). lts melting point was 173 to l74C. A solution of this compound in benzene was colorless, but immediately turned blue upon being irradiated with sun light, and returned to colorless soon after being placed in the dark.

The material obtained by coating a solution of this compound in an ethyl acetate solution of polyvinyl acetate onto a polyethylene terephthalate film and then drying it was colorless in the ordinary state, but im mediately changed to dark blue when irradiated with ultraviolet rays, and returned back to its original colorless state upon being placed in the-dark for a short time.

EXAMPLE 4 3.4 g. of l-'y-cyanopropyl-2,3,S-trimethyl-S- chloroindolenium bromide and 1.7 g. of S-nitrosalicylaldehyde were reacted in the same manner as in Example to obtain 2.0 g. of the yellow crystals of l-ycyanopropyl-3,3-dimethyl-5-chloro-6'-nitrospiro(indoline-2,2'-2'l-l-chromene). lts melting point was 198 to 200C. The properties of this compound were almost the same as that in Example 1.

EXAMPLE 5 3.4 g. of l-B-ethylcarboxyethyl-2,3,3 ,5-

tetramejhylinedolenium bromid and L? of 5- mtrosalicylaldehyde were reacte m the same manner as in Example 1 to obtain 1.8 g. of the yellow crystals of l-B-ethylcarboxyethyl-B ,3 ,5-trimethyl-6'=-nitrospiro( in doline-2,2'-2'H-chromene). lts melting point was 98 to 99C. The properties of this compound were the same as that of Example 1.

We claim:

1. A photochromic compound represented by the following formula wherein R, and R each is an alkyl group having one to five carbon atoms or a phenyl group, R is a hydrogen atom, an alkyl group having one to five carbon atoms, a halogen atom, a nitro group, a cyano group, a carboxyl group substituted by an alkyl group having one to five carbon atoms, or methoxy group, R and R each is a hydrogen atom, a nitro group, a halogen atom, a formyl group or a methoxy group, X is a cyano group or a carboxy group substituted by an alkyl group having one to five carbon atoms and n is l to 4.

2. The photochromic compound as claimed in claim 1 wherein said compound is l-y-cyanapropyl-3,3- dimethyl-6'-nitrospiro(indoline-2,2'-2'H-chromene).

3. The photochromic compound as claimed in claim 1 wherein said compound is l-y-ethylcarboxypropyl- 3,3-dimethyl-6'-nitrospiro(indoline-2,2'-2H- chromene).

4. The photochromic compound as claimed in claim 1 wherein said compound is l-y-cyanopropyl-3,3- dimethyl-6'-nitro-8-methoxyspiro(indoline-2,2'-2'H- chromene).

5. The photochromic compound as claimed in claim 1 wherein said compound is l-y-cyanopropyl-3,3-

(indoline-2,2'-2 H- 

2. The photochromic compound as claimed in claim 1 wherein said compound is 1- gamma -cyanapropyl-3,3-dimethyl-6''-nitrospiro(indoline-2,2''-2''H-chromene).
 3. The photochromic compound as claimed in claim 1 wherein said compound is 1- gamma -ethylcarboxypropyl-3,3-dimethyl-6''-nitrospiro(indoline-2,2''-2''H-chromene).
 4. The photochromic compound as claimed in claim 1 wherein said compound is 1- gamma -cyanopropyl-3,3-dimethyl-6''-nitro-8''-methoxyspiro(indoline-2,2''-2''H -chromene).
 5. The photochromic compound as claimed in claim 1 wherein said compound is 1- gamma -cyanopropyl-3,3-dimethyl-5-chloro-6''-nitrospiro (indoline-2,2''-2''H-chromene).
 6. The photochromic compound as claimed in claim 1 wherein said compound is 1- Beta -ethylcarboxyethyl-3,3,5-trimethyl-6''-nitrospiro (indoline-2,2''-2''H-chromene). 